Sometimes you need globally unique identifiers, such as for ISRCs. One way to approach this is by using URIs – the uniqueness of the domain part of URIs is administered by ICANN, the uniqueness of the rest of the URI is administered by the owner of the domain. There’s a good balance between centralization and decentralization.
But ownership of domains changes, and when it does the identifiers associated with one ownership become invalid. Many types of identifiers, including ISRCs, need to be persistent. So you couldn’t use URLs for these.
This could be corrected by adding a date to the identifier. The new identifier would be a URL/date pair, like
[“January 1, 2000”,”http://example.com/1234”]
The date specifies a point in time when the identifier was valid. So if there is a valid identifier http://example.com/1234 on January 1, 2000, and then example.com comes under new management which doesn’t support this identifier, the dated URL continues to be valid.
This only works for URIs used as identifiers and not for URIs used as locators. Adding the date would not restore an old URI that was out of service.
4 thoughts on “Dated URIs”
That’s an incredibly interesting document. Really fun thinking.
Kick it up a notch:
– Use URIs as identifiers
– Retrieving that URI gives you a graph of facts
– Some of those facts are about other “external” identifiers.
– It’s all distributed and people can’t agree on everything.
IE: http://whitehouse.gov/enemies# states that the organisation identified by http://wikileaks.org/ is a criminal organisation.
… and you get into a whole lot of interesting Trust issues.
http://www.w3.org/TR/prov-dm/ is an attempt at attributing statements to agents/authors and tackles concepts like
– X stating a fact
– X stating on behalf of Y
– X calculating a fact from A + B + C
– X stated a fact at revision 1, X stated a contradiction of that fact at revision 2.
OTOH, the ability to retrieve a URI isn’t persistent. Ownership of the domain will vary over time. You’d need to associate retrievals with dates to make them persistent.